Counterbalancing device



Feb. 25, 1941. P N K I 2,233,029

COUNTERBALANCING DEVICE Filed June 14, 1958 2 Sheets-Sheet 1 Feb. 25, 1941. K. T. PENICK COUNTERBALANCING DEVICE Filed June 14, 1938 2 Sheets-Sheet 2 Patented Feb. 25, 1941 half to Arthur J. Penick, Harris County, Tex.

Application June 14, 1938, Serial No. 213,561

7 Claims.

This invention relates to 'a pumping unit designed for use in pumping deep wells such as oil wells and has particular relation to novel means for operating the walking beam to which the pump sucker rods are attached so as to counter-balance the rods.

It is an object of the invention to provide certain improvements over that type of pumping unit disclosed in the patent to George B. Gordy, Jr., No. 2,117,716, dated May 1'7, 1938, and a particular object of the invention is to provide means for utilizing fluid under pressure as counter-balance means during the pumping operation and for reducing the amount of work required to pump a well.

It is another object of the invention to provide means for compressing a fluidon down stroke of the sucker rods to counter-balance the down stroke and on the upstroke to counter- 0 balance the string of rods by means of this compressed fluid and in this connection to provide means for adjusting or regulating the compression of the counter-balancing fluid to the end that a proper counter-balance may be maintained under varying pumping conditions encountered.

It is a further object to provide novel means for attaching'the piston connecting rod to the walking beam.

With the above and other objects in View, the invention has particular relation to certain novel features of construction, operation and arrangement of parts, an example of which is given in this specification and illustrated in the accompanying drawings, wherein:

Figure 1 shows a side elevation of the unit.

Figure 2 shows a side View, partly in section, of the counter-balancing cylinder, and associated parts, and

Figure 3 shows a cross sectional view taken on the line 3-3 of Figure 2.

Referring now more particularly to the draw ings wherein like numerals of reference designate the same parts in each of thefigures, the

numeral I designates the prime mover which is 0 beam 5 through the pitman 6. The walking beam isiulcrumed on aSamson post I, which is tubular in form and forms a reservoir for compressed fluid. l

The walking beam is medially fulerumed on the Samson post by means of a trunnion 8 and the pitman 6 is connected to the rear end of the walking beam by universal joint 9. A cable H) which supports a polish rod saddle II, is connected to the front end of the walking beam and a polish rod I2 is suspended from the saddle, for L reciprocating -a usual string of sucker rods through which the usual deep well pump is operated.

' The unit also includes a cylinder l3 which is supported on an upstanding bracket [4 of'the foundation l5; and a piston 16, which works in the cylinder I3 and which is connected to the lower end of a tubular piston rod H. The cylinder and piston l3, l6 provide means for partially counter-balancing the string of reciprocating sucker rods. As an instance of this arrangement, the piston rod H for the piston 16 is preferably connected to the walking beam 5 between the Samson post I and the pitman 6. For the purpose of forming this connection, a cap I8 is fastened on the upper end of the connecting rod 8 and whose upper end is provided with a port 19. The cap 18 has the laterally extended trunnions 2B, 20, on which are pivotally mounted the cable sockets 2|, 2|, to which the free ends of the cable loop 22 are attached, said cable working over the curved surface of the head 23, which is secured in any suitable manner to the walking beam. The piston rod I1 works through a suitable stuffing box 24 of the cylinder head 25, the upper end of the cylinder [3 being thereby closed. The portion of the cylinder I 3 which is below the piston I5 is open to the atmosphere by way of a port or ports 26 and the piston seals against the escape of pressure from that portion of the cylinder which is above the piston.

By this arrangement, the piston I6 is elevated in the cylinder l3 on the down stroke on the string of sucker rods thereby compressing the fluid in the cylinder 13. This compressed fluid is discharged by way of a conduit 21 one end of which is connected into the reservoir formed by the Samson post I and its other end is connected with the connection 28 of the cylinder head whereby the cylinder l3 is placed in communication with said reservoir. The conduit 21 is equipped with a shut off valve 29 whereby the conduit may be opened or closed at will. The fluid which is compressed is preferably air and the reservoir in the Samson post I is initially filled with compressed air and the pressure in the reservoir is maintained by the compressed air which is supplied thereto on the downstroke of the string of sucker rods. The down stroke is thus counter-balanced by the air which is partially compressed in the cylinder I3 and which is discharged into the reservoir I by way of the conduit 21. On the upstroke of the string of sucker rods compressed air from the reservoir I is supplied to the cylinder I3 through the conduit 21 and this pressure exerted against the piston l6, thus counter-balancing the upstroke of the string of rods.

Additional means are preferably provided for compressing fluid and counter-balancing the downstroke of the string of sucker rods and this compressed fluid may be utilized to maintain the desired pressure in the reservoir I. purpose additional air may be compressed on the downstroke of the string of sucker rods and this additional compressed air may be supplied to the reservoir I. For this purpose the piston rod I! is formed hollow, thus providing an auxiliary cylinder which, at its upper end is open to the atmosphere by way of the port I9 and at its lower end, is open through the piston I6 and a pipe 3| is extended upwardly through the piston I6 into the auxiliary cylinder 30 and a seal 32, suchas a stuffing box is carried by the piston I6 and closely surrounds the pipe 3|. The lower end of this pipe 3| is connected, preferably by a flexible hose 33, into the lower end of the reservoir 1 and this hose is equipped with a suitable valve 34 whereby the conduit through it may be controlled at will. There is a suitable packin head 35 on the upper end of the pipe 3|, which permits reciprocation of the piston rod II relative to the pipe 3|, with the packing head sealing that portion of the auxiliary cylinder 3!] below the packing head .and the lower end of said auxiliary cylinder is sealed by the The upper end of the pipe 3| communicates with the auxiliary-cylinder 30 by way of ports as 36 and a valve 31 which is yieldingly held closed by a spring 38, which closes the escape of pressure from the pipe 3| to the auxiliary cylinder 33 through said ports, but, is adapted to open responsive to pressure in the auxiliary cylinder to permit flow from the auxiliary cylinder through the ports 36 and past the open valve into the pipe 3|. On the up stroke of the string of sucker rods with the piston I6 moving downwardly relative to the stationary head 35 the pressure in the reservoir 1 closes the ,valve 3'! so that compressed air from the reservoir'is shut off from the auxiliary cylinder 30 and the upstroke of the string of rods is thus counter-balanced entirely by the compressed air supplied to the cylinder I3 which is exerted against the piston I6. On this downstroke of the piston It, the packing cups 39 yield responsive to the partial vacuum which is formed in the auxiliary cylinder 30 below the head 35. The packing cups 39 are arranged with their open ends downwardly, as illustrated in Figure 2, so that air at atmospheric pressure supplied through the port I9 is drawn into that portion of the auxiliary cylinder below the head 35.

The air which, during the down stroke of the piston I6, is thus drawn into the auxiliary cylinder 30 below the head 35, is compressed on the upstroke of the piston I6, that is, on the downstroke of the string of sucker rods, and this compressed air opens the valve 31 so that the air which is compressed in both the cylinder l3 and the auxiliary cylinder 30 is supplied to the reservoir 1 during this down stroke of the string of rods. This compression in the auxiliary cylinder 30 in addition to the compression in the cylinder I3, counter-balances the downstroke of the string For this of rods and compresses the air to a degree whereby it may be forced into the reservoir I against the pressure therein. The maximum pressure in the reservoir may be controlled by a safety valve 43.

Depending from the bottom plate 4| by means of which the cylinder I3 is supported by the bracket I4, there is a sleeve 42, through which the lower end of the pipe 3| extends and secured around the lower end of the sleeve 42 there is a clamp 43 with which the nut 44 has a swivelling connection. This nut may be turned by the grip members 45, 45 and it has a threaded connection with the lower end of the pipe 3| as shown in Figure 2, whereby upon turning of the nut 44 the pipe 3|, and the packing head 35 carried thereby, may be adjusted up or down in the auxiliary cylinder 30, the hose 33 being flexible to permit this adjustment.

If the sucker rods overbalance the compression in the Samson post I, the packing head 35 may be adjusted downwardly so as to increase the compression and bring the walking beam 5 into balance.

The lower end of the pitman 6 may be adjusted on the crank 2, so as to increase or decrease the stroke of the walking beam and in that event a corresponding adjustment of the packing head 35 should be made to correspondingly regulate the compression in the compression reservoir or Samson post I.

What I claim is:

1. A counterbalancing device for use with the walking beam of a well pumping unit, comprising the combination of a reservoir, a cylinder, a hollow piston rod, a piston connected to the rod and mounted on the cylinder, constituting an air cushion in connection with the walking beam, a closure for the hollow piston rod, a pipe extending into the hollow piston rod through said closure, a packing head on the pipe engaging the Walls of the hollow piston rod, a valve between said pipe and the interior of the hollow piston rod, said valve closing responsive to pressure in the pipe and opening responsive to pressure in the hollow piston rod, the parts being arranged whereby movement of the piston in one direction compresses fluid in the cylinder and in the interior of the hollow piston rod, and'movement of the piston in the opposite direction draws atmospheric air past the packing head and into the interior of the hollow piston rod, means for conducting compressed air from the cylinder and the interior of the hollow piston rod to the reservoir during movement of the piston in the first mentioned direction, means for supplying compressed air from the reservoir to the cylinder during movement of the piston in the opposite direction, means for adjusting the packing head in the hollow piston rod and means for oscillating the walking beam.

2. A counterbalancing device for use with the walking beam of a well pumping unit, comprising the combination of a cylinder, a hollow piston rod, a piston connected to the hollow piston rod and mounted in the cylinder, constituting an air cushion in connection with the walking beam, the hollow piston forming an auxiliary cylinder, a pipe extending into the auxiliary cylinder, mean surrounding the pipe for closing one end of the auxiliary cylinder, a packing head on the pipe expanded by pressure in the auxiliary cylinder for sealing the opposite end of the auxiliary cylinder, means for adjusting said pipe and packing head longitudinally relative to the auxiliary cylinder, at fluid inlet communicating with the hollow piston rod beyond the packing head, a valve between the pipe in the auxiliary cylinder, said valve closing responsive to pressure in the pipe and opening in response to pressure in the auxiliar cylinder, the parts being "arranged whereby movement of the piston in one direction compresses fluid in the cylinders and movement of the piston in the opposite direction draws fluid through the fluid inlet and thence through the hollow piston rod and past the packwhereby movement of the hollow piston rod responsive to downward movement of the walking beam, operates the piston for compressing fluid in the cylinder, means in the hollow piston rod for compressing fluid therein by said movement of the hollow piston rod, means for adjusting the compressing means in the hollow piston rod for regulating the compressive influence thereof,

means for conducting compressed fluid to the reservoir from the cylinder and from the hollow piston rod, said conducting means supplying compressed fluid from the reservoir to the cylinder and against the piston for moving the hollow piston rod in the opposite direction during upward movement of the walking beam, means for shutting off compressed/fluid from the hollow piston rod during said upward movement of the walking beam and means for reciprocating the string of rods.

4. A counterbalancing unit for use with the walking beam of a pumping mechanism, a reservoir, a cylinder, a piston, a hollow piston rod, the piston and its hollow piston rod being adapted for reciprocation in the cylinder, and means whereby movement of the piston and its hollow piston rod in one direction compresses fluid in the cylinder and in the hollow piston rod with said compressed fluid supplied thence to the reservoir, said means being so arranged that during movement of the piston and its hollow piston rod in the opposite direction, said compressed fluid is shut off from the reservoir to the hollow piston rod, but is supplied from the reservoir to the cylinder for exerting pressure against thepiston in said opposite direction and means for regulating the volume of compressible fluid in the hollow piston rod.

5. A counterbalancing device comprising a reservoir, a cylinder, a piston, a hollow piston rod, the piston and its hollow piston rod being ,adaptedfor reciprocation in the cylinder, means whereby movement of the piston and its hollow piston, rod in one direction compresses fluid in the cylinder and in the hollow piston rod with said compressed fluid supplied thence to the reservoir, said means being arranged so that during movement of the piston and its hollow piston rod in the opposite direction, said compressed fluid is supplied from the reservoir to the cylinder for exerting pressure against the piston in said opposite direction and means for regulating at will, the volume of compressible fluid in the hollow piston rod.

6. A co'unterbalancing device for use with a well pumping mechanism which includes a Walking beam in connection with a string of pump operating rods, said device comprising the comhination of a reservoir, a cylinder, piston and hollow piston rod constituting a cushioning means for the walking beam in its operation, means whereby movement of the piston and its hollow piston rod in one direction compresses fluid in the cylinder and in the hollow piston rod with said compressed fluid supplied thence to the reservoir, said means being arranged so that during movement of the piston and its hollow piston rod in the opposite direction, said compressed fluid is supplied from the reservoir to the cylinder for exerting pressure against the piston in said opposite direction and means for regulating the volume of the compressible fluidin the hollow piston rod at will.

7. The combination of a reservoir, a cylinder, a piston in the cylinder, a hollow piston rod connected to the piston all constituting cushioning means for a walking beam of a pumping mechanism dulring operation of the beam, means whereby movement of the piston and its hollow piston rod in one direction compresses fluid in the cylinder and hollow piston rod and delivers the same tothe reservoir, said means being arranged so that during movement of the piston and its hollow piston rod in the opposite direction said compressed fluid is supplied from the reservoir to the cylinder for exerting pressure against the piston in said opposite direction, said means including a piston in the hollow piston rod and means for adjusting the piston in the hollow piston rod for regulating the volume of the compressible fluid in the hollow piston rod at will.

KIRBY T. PENICK. 

